Sound distributor



1,560,637 Nov 1925 c. ANDERSEN ET AL SOUND DISTRIBUTOR Patented Nov. 10,1925.

UNITED STATES p I meant;

PATENT, QFFHIE.

cam. annnnsnn AND ,AAGE CHRISTIAN sYLvEs'r, or coennnaenn, nnnivranx.

SOUND DISTRIBUTOR.

Application filed August 13, 1924. Serial No. 731,824.

To aZZ whom it may concern Be 1t known that we, CARL ANDERSEN and 'AAGECHRISTIAN SYLvEs'r, citizens of Denmark, and both residing atKobmagergade 59, Copenhagen, Denmark, have invented certain new anduseful Improvements in Sound Distributors, of which the following is aspecification.

The invention relates to a sound distributor, especially for radiotelephony, by means of which the sound emitted from the diaphragm of oneor two listening teler. phones may be distributed uniformly to arelatively large number of persons, and may be reinforced at the sametime.

The apparatus is mainly characterized in that the sound from thetelephones is projected towards the point of a cone which is disposedwithin a hollow body made of ebonite, or the like. From the cavity ofsaid body hoses extend in all directions by way of which the reinforcedsound is directed to the ears of the various persons, and in this mannerthe sound in its entirety is distributed in perfectly uniform andregular manner to all the listeners.

The apparatus may be varied considerably in detail, and one constructionis illustrated on the drawing, in which- Fig. 1 shows the apparatusmainly in vertical section and Fig. 2 the same in cross-section alongthe line AB in Fig. 1.

In the construction illustrated, use is made of a hollow body 1, open atboth ends and consisting of ebonite, caoutchouc or some other suitablematerial and being adapted to be placed vertically as shown, or elsehorizontally or in some other desired direction.

In the cavity of this body there is attached in suitable manner amassive body made similarly of ebonite, wood or other hard material,having at its centre a cylindrical portion 2 and tapering at both endsinto a cone point 3 nearly reaching the end of the body 1, a cavity 4:being formed between each of these cones and the cylindrical portion 2.

From each of the cavities of the body 1 radial channels are extending,into which the tubes 6 connected to the distributing hoses 5 may beinserted. As shown in Fig. 1 the said tubes are expanded funnel-wisetoward the cavity in order to be better adapted to catch the sound. Atthe opposite end of each hose there is provided a suitable hook-shapednozzle 7 with a suitable shapeda recess 9 in order to fit firmly "intothe ear; In case not all the hoses 6 are being used, a plug 10 may beinserted into the corre' sponding radial channels, in such manner thatthe cavity remains closed.

Ina-n apparatus of this kind with two cavities and two circular rowso-fdistrib 'head 8' the rear edge of which is fitted with uting hosesuse is also made of two ordinary- I listening telephones 11, which areplaced in such a manner tightly against the open ends of the body 1that'their dia'phragms will be i placed immediately against the cavitiesnd the cones '3.

In order to keep the telephones pressed tral opening 16 for passage forthe cord connection of the telephone, if the formeris disposed on theback side of the telephone.

Besides there are provided openings 17 in the plate 12 adapted toaccommodate adjusting knobs 18, which may be provided on the back of thetelephone. As shown in Fig. 1, a packing ring 19 of'soft rubber may beinserted between the listening telephone and the body 1 in order toprevent the loss of any portion of the sound.

The frame may be: of other suitable shape than theone shown, and insteadof using such a. frame the listening telephones and the extreme portionsof the body 1 may be fitted, as shown underneath in Fig. 1, withcorresponding screw threads 20, so that the parts may be screwedtogether, any special devices for holding the parts together being thusrendered superfluous.

The projecting cones in the cavity of the body 1 form good distributingmembers for the sound, while the cavities 4 provide resonance, in such amanner that the sound is not only distributed uniformly to all thelisteners, but is also reinforced in the said cavities. As the latterare made absolutely tight, the entire sound will be distributeduniformly to all sides, and may be heard distinctly and clearly by up totwenty pensons.

Instead of being constructed for two telephones, the apparatus may ofcourse be made for a single one, so that there is provided only onedistributing cone and one single row of hoses 5.

The body 1 may be of polygonal out-side shapecinstead of beingcylindrical. Besides the tubes 6 as well as the plugs 10 may be' sohollowed at their inner end, that their end faces will lit the cylinderwall of the cavity.

Having now describe-d our invention, what we claim is:

1. In an apparatus for reinforcing and distributing the sound from twotelephones each having a diaphragm, a distributing cone facing eachdiaphragm, a hollow body in which said cone is arranged and fixed infront of the diaphragm of each telephone.

2.,In an apparatus for reinforcing and distributing 'the sound irom twotelephones,

each having a diaphragm, a distributing cone facing the diaphragm, a.hollow body 111 which said cone 1s arranged and fixed infront of thediaphragm of each telephone, I

packing rings between said hollow body and said telephones and anadjustable frame forming a base for the apparatus and in which saidcliaphragins and hollow body are arranged, said frame serving to presssaid diaphragms against the ends of said hollow body.

3. In an apparatus for reinforcing and distributing the sound from twotelephones, each having a diaphragm, a distributing cone, a hollow bodyin which said cone is arranged and fixed in front of the diaphragm ofeach telephone, said hollow body and said telephones having screwthreads by means of which the parts are interconnected.

In witness whereof we ailix our signatures. I

CARL ANDERSEN.

AAGE CHRISTIAN SYLVEST.

